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Air Fronts: Aircraft Manuals - RAF Pilot's Notes: A.P 2095, Pilot's Notes - General, 1943 - Part 4: Emergencies

A.P 2095, PILOT'S NOTES GENERAL, PROMULGATED BY ORDER OF THE AIR COUNCIL , 2ND Edition , April 1943. FOR OFFICIAL USE ONLY

PART IV - EMERGENCIES

NOTE A - ENGINE FAILURE OF TWIN-ENGINE AIR-CRAFT DURING TAKE-OFF

1. Introductory.

(i) The action to be taken in the event of engine failure during take-off depends upon the airspeed attained, on the single-engine performance at the load being carried, and to some extent on the height-that has been reached.

(ii) A safety speed is quoted in the Pilot's Notes which is the speed that should be attained before the pilot starts to climb the aircraft. For twin engine aircraft the safety speed is generally determined by the possibility of keeping the aircraft straight by prompt correct action without throttling back if one engine fails suddenly at take-off power. (Safety speed is otherwise determined by the possibility of getting the nose down from a climbing attitude after engine failure and avoiding a stall.) Safety speed is one basic factor in deciding upon the action to be taken.

(iii) Another factor is the ability of the aircraft to climb at the weight at which it is being taken off, or at the figure to which the weight can be reduced by jettisoning load if time permits.

(iv) Height attained is a further factor in so far as it gives more or less scope for action, e.g. to jettison load or to raise flaps.

(v) A failure of both engines calls for the same action as on a single engine aircraft; these notes are concerned with a failure of one engine only.

(vi) The pilot should keep a hand on both throttles until the undercarriage is up and safety speed has been attained.

2. Failure before becoming Airborne.

If failure occurs while still on the ground, stay on the ground and pull up as quickly as possible:

(a) Close both throttles.

(b) Pull up on the brakes; and switch off to assist braking, if possible. If the space ahead is insufficient, swing the aircraft, if it is not travelling too fast; or retract the under-carriage, if that can be done.

3. If Airborne but below Safety Speed.

Land at once straight ahead :

(a) Close both throttles at once, checking any swing and roll with the rudder and ailerons, and put the nose down.

(b) At night, switch on the landing lamp.

(d) Select flaps down.

(e) Land straight ahead, or with. only slight change of direction to avoid an obstacle.

(f) Turn off fuel and switch off.

4. Above Safety Speed - Immediate Action.

Whether the aircraft can climb or not, the following is the action to take in the first place. If the aircraft will not climb and the height is very low it may not he possible to complete the procedure before landing; the drill should be followed through so far as is practicable in the circumstances :

(a) Keep straight by instant and coarse use of the rudder; keep the wings level by instant and coarse use of the ailerons, and put the nose down to maintain or gain speed. (A few degrees of bank towards the live engine will assist in keeping straight.)

(b) See that the undercarriage is up or rising.

(d) Trim the rudder as necessary to relieve foot load.

(e) Close the cowling gills or radiator shutters.

(f) Jettison bomb load.

NOTE. - If the flaps have been used for the take-off they will generally impair the power to climb on one engine and should be raised if or when a safe height has been reached, unless it is certain that climbing is impossible. Any change of trim or tendency to sink must be quickly counteracted by movement of the stick.

5. Above Safety Speed - Subsequent Action.

(i) The pilot may know definitely whether he can or cannot climb in the circumstances and will then at once act accordingly. If he is in doubt, he should carry out the Immediate Action of para. 4 so far as time permits and test his ability to climb at the speed quoted in the Pilot's Notes as the best speed for maintaining height on one engine.

(ii) If the aircraft will not climb, a landing must be made ahead. The live engine may be used to stretch the descent to reach a more favourable landing place; but care must be taken not to let the speed fall below safety speed. Land as in para. 3.

(iii) If. the aircraft will climb, a gentle turn may be started above 500 feet, always towards the live engine, and the aircraft flown to the leeward side of the airfield preparatory to landing. Climb, if possible, to at least 1,000 feet.

6. Note on Use of Engine.

The use of take-off power may be continued so long as it is really necessary; r.p.m. and boost should be reduced to the climbing limitations as and when it becomes safe to do so, and cowling gills or radiator shutters on the live engine should be opened as necessary to avoid overheating.

PART IV-NOTE B - ENGINE FAILURE OF TWIN-ENGINE AIR-CRAFT DURING A FLIGHT

1. Introductory.

(i) In this Note the aircraft is assumed to be flying at a safe speed and height, and to be capable of maintaining a safe height after jettisoning any bombs not already re-leased. If failure occurs early in the flight it may be necessary to jettison part of the fuel to make the aircraft capable of level flight.

(ii) The Note discusses the immediate action to get the aircraft under full control and prepared for single-engine flight, and the subsequent action to reach and maintain a suitable height for the return. The landing is discussed in the next Note.

2. Immediate Action.

(i) If the failure is clearly due to a mechanical breakdown of the engine, or accompanied by fire (see Note G), the propeller should be feathered at once. In other circumstances the cause of failure should be investigated before feathering :

(a) Keep straight and level by instant and coarse use of the rudder and ailerons, putting the nose down as necessary to maintain speed. (A few degrees of bank towards the live engine will assist in keeping straight.)

(b) Trim the rudder as necessary to relieve foot load.

(d) Reopen this throttle slowly to see if any power is available. If not, close again.

(e) Set propeller lever fully back.

(f) Open up the live engine as necessary and retrim.

NOTE.-When the pilot is dependent on instruments, it is advisable to throttle back both engines at once, putting the nose well down, and then to reopen the live engine slowly. See that the cock for the gyro instruments is set to the live engine.

The pilot should now make a systematic check of some possible causes of failure :

(a) Check fuel contents, cocks, pressure, booster pumps.

(b) Carburettor icing (see Part II, Note F).

(c) If flying on WEAK mixture setting, try RICH. (If there is no manual mixture control, the engine may run at a boost above the weak mixture limit.)

(iii) If the failure cannot be rectified:

(a) Feather (or set to POSITIVE COARSE pitch) the propeller of the failed engine and switch off the ignition.

(b) Close the cowling gills or radiator shutters of the failed engine.

3. Subsequent Action.

(i) Any remaining bomb load should be jettisoned.

(ii) The pilot should check over any possibilities of reducing drag by retracting turrets, seeing that flaps and under-carriage are fully up and bomb doors properly closed. Close all apertures as far as possible.

(iii) Maintain at least the I.A.S. given in the Pilot's Notes as the best speed for maintaining height on one engine. If the speed falls below this best speed, considerable height may be lost in regaining speed. (If the speed is not stated in the Pilot's Notes, maintain at least a

4. Range on One Engine.

(i) Range on one engine is generally much less than on two since a 25 to 35% richer mixture is used at the higher boost needed for single-engine flight, leading to a corresponding reduction of range.

(ii) Maximum range will be obtained by flying, if possible, a little below the normal economical return speed, and by making any possible reduction of power below the climbing limitations by reducing the r.p.m. (unless it is possible to reduce boost to the weak limitation).

DIAGRAM SHOWING HOW' THE POWER TO CLIMB VARIES WITH ALTITUDE AND WITH AIRSPEED.

PART IV-NOTE C - APPROACH AND LANDING ON ONE ENGINE IN TWIN-ENGINE AIRCRAFT

1. Introductory.

(i) Undershooting may involve the pilot in a situation from which he can only extricate himself with difficulty and/or damage to the aircraft.

(ii) Weather conditions permitting, surplus height should, therefore, be kept in hand against the possibility of undershooting when the undercarriage is lowered.

(iii) If weather conditions prevent the normal height being used for the approach, or if visibility is such that judgment is difficult, diversion to another airfield should be made, if possible.

(iv) Lowering of the undercarriage should be delayed until approaching the leeward side of the airfield because, on most types, it will make it impossible to maintain height on one engine.

(v) It must, however, be borne in mind that, if only half hydraulic power is available, or if the handpump has to he used, the undercarriage will take longer to come down. The aim should he to have it locked down just before starting the final approach, so that the various checks do not distract attention from the approach itself.

vi) On types on which single-engine flying with under-carriage down is difficult, an approach with wheels lowered should not be attempted under low cloud.

2. Approach and Landing.

(i) Lower and check the undercarriage as late as is convenient.

(ii) Lower the flaps part way when across wind, as in a normal approach. (The maximum setting recommended for take-off is suitable.)

(iii) An engine-assisted approach must not be attempted. Make a glide approach at the speed for single-engine approach recommended in the Pilot's Notes. If this speed is not given, approach a little faster than the normal glide approach speed, allowing for the weight at which the aircraft is flying.

(iv) Ease off not more than half the rudder trim, as it may be necessary to open up somewhat. Use of the live engine to correct undershooting should be made as early as possible in the approach.

(v) The flaps should be lowered fully only when certain of getting into the airfield, unless earlier use is necessary to correct definite overshooting.

3. Undershooting.

(i) Any tendency to undershoot must be corrected in the early stages by careful partial use of the live engine, taking great care to maintain or increase speed. The later undershooting is corrected, the more power will be needed. Stretching the approach will cause a tendency to lose speed, making it more difficult to hold the aircraft straight and level against the increased power. The point at which the tendency to yaw and roll can no longer be held usually occurs well below full power, and it is seldom possible to fly level-on one engine with undercarriage lowered and flaps partly down.

(ii) If there is definite undershooting, or any doubt whether the necessary power can be held:

(a) Close the throttle.

(b) Depress the nose to maintain or increase speed.

(d) Lower the flaps fully.

(e) Land short of the airfield.

4. Mislanding.

On some types it may be possible to go round again if at 500 feet at least it is decided that the approach has been badly misjudged; below this height no attempt can safely be made.

(a) Ensure that speed is sufficient, if necessary putting the nose down.

(b) Open the throttle.

(d) Raise the flaps by stages

PART IV-NOTE D - ENGINE FAILURE IN FOUR-ENGINE AIRCRAFT

1. General.

(i) The pilot of the four-engine aircraft should be familiar with the principles laid down in the preceding notes A, B and C, which apply in the event of- a failure on a four-engine aircraft in greater or less degree according to which engine fails-inner or outer, port or starboard.

(ii) As the failure of a single engine deprives the pilot of only a quarter of the total power, the ability to maintain height and to climb will be less seriously affected than by engine failure on a comparable_ twin.

(iii) Failure of an inner engine will cause considerably less difficulty in control; failure of an outer engine will, in general, be comparable in the control problem with failure on a twin; simultaneous failure of both engines on one side may be expected to present a more serious problem, calling for very careful attention to the principles of Notes A, B and C.

(iv) These Notes are essentially general and pilots should consult the Pilot's Notes for the special characteristics and capabilities of particular types.

2. Take-off Failures-Note A.

(i) The principles of Note A are fully applicable in the event of failure of an outer engine, except that the power to climb will be less seriously affected than on a twin of similar weight per horse power.

(ii) Safety Speed is quoted in Pilot's Notes in relation to an outer engine failure. With an inner engine failing, it may be safe to attempt to climb away from a lower speed, this depending on the three-engine performance of the type at the take-off load, with which the pilot should be familiar.

(iii) Failure of one engine (especially an inner engine) may not be readily noticeable at once. The pilot must be guided by the feel of the aircraft-by tendency to swing and poor acceleration-in deciding upon the action to he taken.

3. Flight Failures-Note B.

(i) Note B applies fully as regards control with an outer engine failure, and fully as regards performance with two engines dead.

(ii) With three engines it will be possible to maintain a considerable height, or to return in weak mixture at a lower' altitude; and it may not be necessary to jettison bombs.

(iii) An engine failure may not be apparent at once, and it may pass unnoticed for some time unless a continued watch is kept upon engine temperatures and/or the maintenance of height and I.A.S. R.p.m. and boost will generally be maintained, and the automatic pilot may mask any tendency to swing. At moderate airspeeds the failed engine can be located by setting all propeller controls for maximum r.p.m. and noting which engine does not rise fully; or falling engine temperatures will reveal the defaulting engine.

4. Landing-Note C.

(i) Landing with two engines dead on one side requires special attention to the principles of Note C.

(ii) Landing with three engines is straightforward and may be engine-assisted, preferably with symmetrical power; but it is important that a decision to go round again be made early in the approach to give ample time to reach the safety speed before climbing away.

PART IV-NOTE E PROPELLER FAILURES

1. Introductory.

The correct handling of the engine and propeller controls, and certain special precautions that need to be taken with certain types of propeller to avoid overspeeding and to ensure correct action, have been dealt with in Part II. This Note contains advice on the action to be taken in the event of a breakdown of the constant-speed mechanism.

2. The Locked Propeller.

(i) If the control should break down and lock the propeller on a climb the pitch will be rather fine. The pilot will be able to cruise home at fairly high r.p.m. He must restrain the r.p.m. by not opening the throttle too fully and by not diving. Climbing power will be good.

(ii) If the locking occurs in level flight the pitch will normally be rather coarse and suitable for all level flight conditions, but not for climbing. The pilot should avoid risking a baulked landing as far as possible.

(iii) If the propeller is one of large pitch range, 35° or full feathering, and if the failure occurs at a high speed in a dive, the pitch may be locked too coarse to permit the use of enough power for level flight and a forced landing will be necessary. (With a 20° propeller it will always be possible to fly home.)

(iv) Before he assumes that the pitch of a hydraulic propeller is irretrievably fixed, the pilot should attempt to free the control by a fairly rapid fore and aft movement of the lever.

3. The Fractured Pipe.

(i) Hydraulic propellers may fail to control through a fractured connection. - The propeller will then tend to one or the other limit of its pitch range, but cannot be returned; and the attempt to return it will cause a rapid loss of engine oil leading quickly to seizure.

(ii) If the r.p.m. tend to rise and cannot be reduced, the pilot. must select maximum r.p.m. and fly so that the r.p.m. are always less than maximum, or he will lose engine oil. This is easily done by reducing I.A.S. if flying fast, and by limiting the throttle opening, which can be wider as the I.A.S. is reduced. (The C.S.U. will then continually supply oil to the sound connection to hold the blades against the fine pitch stops.) The pilot must not attempt to feather.

(iii) With the De Havilland 20° propeller the only hydraulic supply failure that can occur will put the pitch into Positive Coarse. When it is impossible to raise the r.p.m. by the propeller control, the pilot must select Positive Coarse Pitch to conserve engine oil.

(iv) With the Rotol 20° propeller a failure can occur in either direction. The pilot must move the lever fully over in the direction in which the r.p.m. tend to go and maintain the r.p.m. below the maximum, or-above the minimum, by the I.A.S. and boost at which he flies. (See (ii) above.)

(v) With the 35° and feathering propellers, if the failure pre-vents fining of the pitch, level flight will not be possible. The propeller should be feathered; or if not a feathering propeller, set to minimum r.p.m. and enough throttle used to keep the r.p.m. above the minimum. This action will keep the oil pressure on the sound connection.

(vi) In the event of fracture affecting both directions it is impossible to prevent loss of engine oil.

4. Electric Propellers.

(i) If automatic control fails, direct "manual" control may still be possible.

(ii) If the propeller is, completely out of control, the safety switch should be opened as a precaution against current wastage discharging the battery.

PART IV---NOTE F - ABANDONING AIRCRAFT BY PARACHUTE

(Notes for all members of air crews)

1. Abandoning Aircraft (multi-seater).

(i) It may be necessary to abandon an aircraft

(a) while it is under control and ample time is available,

(b) in emergencies in which speed of exit is vital.

(ii) In case (a) the crew should act deliberately, using the available time to ensure exact execution of the "abandon aircraft drill" and, consequently, safe exit and descent.

(iii) In case (b) each man must generally leave by the nearest exit with the greatest speed, but the recommended exits should be used when possible, since other exits may be dangerous.

(iv) The recommended exits are marked PARACHUTE EXIT in white letters and the drill lays down the appropriate exit for each member of the crew.

(v) The captain of the aircraft is responsible for the decision and for giving the order "abandon aircraft". He must maintain control (so far as possible) and leave last.

(vi) Other members of the crew carry out the several duties prescribed in the drill (including jettisoning of trailing aerial), move to the prescribed exits and leave the aircraft in the prescribed order.

(vii) Each man should check that his parachute is correctly attached and that oxygen pipes and 'phone leads are disconnected (or helmet discarded.)

(viii) If the descent is made from a high altitude, the use of oxygen should be continued to the last possible moment, for a man without oxygen may lose consciousness in one or two minutes in the activity of leaving an aircraft at 25,000 to 30,000 ft.

(ix) If the descent may be into water the collar and tie (if worn) should be loosened before jumping or during descent.

2. Abandoning Aircraft (single seater).

(i) Radio position.

(ii) Detach all leads connecting pilot to aircraft. Check dinghy "dog lead" attached.

(iii) Leave by the method recommended in the Pilot's Notes.

3. Descent before Opening of Parachute.

(i) If a man leaves the aircraft by falling out backwards or forwards with raised knees, he invariably somersaults and continues somersaulting while he is bunched up. The parachute will open correctly, but the somersaulting is liable to continue as the lift webs are pulled out and the webs may pass between the legs. When the parachute is fully. open the body may be hanging head down, which is uncomfortable and may be dangerous. Somersaulting should be checked before pulling the rip-cord by slowly straightening the legs, keeping them together.

(ii) The rip-cord handle should be grasped before leaving the aircraft. If, however, this has not been done the best and quickest method of finding the rip-cord handle is to look for it. Once clear of the aircraft, the body soon loses speed, the rush of air past the face becomes relatively slight and the eyes can be opened easily, without goggles. Movement of the limbs is normal. On the other hand, oil or injury to the eyes, or darkness may prevent seeing the handle, and all personnel should be familiar with the position and operation of the rip-cord handle and quick-release so they can quickly feel for and find them.

(iii) The parachutist should be well clear of the aircraft and allow time for his motion to slow down before he pulls the rip-cord. The parachute should be released by giving the handle a twist, to pull one corner out of the pocket first, and then a quick jerk. The arms should then be folded across the chest to keep the harness in place during opening.

3. Control during Descent.

(i) Swinging.-Parachutes tend to oscillate, especially at high altitudes, and this swinging tends to cause air-sickness, particularly in rarefied air. Swinging can be stopped by pulling down vigorously on the lines on the opposite side, i.e. pulling on the left lines while the body is swinging to the right, and vice versa. The parachutist should look up at the canopy, which both assists him in checking the swing and reduces the inclination to nausea.

(ii) Sideslipping.-The parachute may be sideslipped during descent by pulling down the rigging on the side towards which it is desired to move. If the canopy partly collapses, it will reopen when the lines are released. By sideslipping, the parachutist has some control of the direction of descent and may be able to avoid a bad alighting area. Since sideslipping increases the rate of descent, the parachutist should aim to fall short of an obstacle rather than attempt to glide over it and sideslipping should not be attempted near the ground, except in emergency.

(iii) Turning.-The parachutist should turn to face in the direction in which he is drifting in the early stages of descent. To turn, grasp a main suspension strap or a handful of lines on the side towards which it is desired to turn and pull down the canopy about three feet. Then grasp a strap or handful of lines on the other side with the other hand and, without pulling down, give a vigorous twist to the canopy in the direction of the turn required. Release the canopy and the body will follow. Do not attempt to turn near the ground, because the process increases the rate of fall.

(There is no Headline 4 in the Original Document - even though the pages are numbered consecutively - Editor)

5. Alighting.

(i) Normal:

The alighting should be made facing down wind, in sitting position, with muscles relaxed. The suspension straps should be grasped with arms fully extended above the head and the body should be pulled up briskly as the feet hit the ground. Keep the body loose and let it roll if necessary.

(ii) In a Strong Wind:

(a) Single Point Release.-Move the release from the locked to the operating setting when at about 10o ft: from the ground and release at the instant that the feet hit the ground.

(b) Parasuit.-Immediately after alighting release the quick-release units.

(iii) In Water:

The "Mae West" should be inflated as soon-as the parachute is open. The water should be entered with legs straight, feet together, elbows to the side, and nostrils pinched together with one hand.

(a) Single point release.-Release the harness with one hand as the feet touch the water.

(b) Parasuit.-On rising to the surface, get clear of the canopy lines and then operate the release hooks.

6. Further Information.

Reference may be made to A.P.1182, Safety Equipment Manual, Volume I.

PART IV-NOTE G - FORCED DESCENT OF LANDPLANES AT SEA

(Pilot's Handling Notes)

1. The Decision.

Radio transmission should begin as soon as the Captain has serious reason to doubt his ability to reach the coast, and at as great a height as possible.

2. Preparation of the Aircraft.

(i) The aircraft should be lightened as much as possible in the time available. Reduction of load both reduces the speed at which it is possible to ditch and increases the buoyancy of the aircraft.

(a) Bombs should be released, but only if there is no doubt that there will be time to close the doors after release. Otherwise retain at "safe".

(b) Fuel should be jettisoned if possible, and the jettison cocks closed.

(ii) If flotation bags are fitted they should be filled before ditching. (Note any special instructions in the Pilot's Notes for the aircraft.)

(iii) Close : Bulkhead doors, Camera and flare chutes and check security of all lower and side hatches.

(iv) Open :- All forward and amidships upper hatches (to facilitate egress and avoid risk of jamming on impact).

3. Personal Equipment.

(i) Life jackets should be worn at all times with the leg straps secured. They should not be inflated until the need for them is near, as they expand at altitude. If the upper exits. are large, jackets may be fully inflated before ditching; but if they are small, jackets should be partially inflated and fully inflated after leaving the exit.

(ii) Parachute harness should be removed when practicable unless it is attached to a single-seater dinghy, when it must he retained.

(iii) Helmets should be retained for protection in the dinghy, with leads tucked firmly into the life jacket.

(iv) Collar and necktie (if worn) should be loosened.

(v) It is vital for the pilot to be secured by Sutton harness.

4. Lights.

(i) At night all bright internal lights should be put out (and only the amber lamps used) to accustom the eyes to the external darkness.

(ii) The landing lamp may be very helpful, but judgment of height by its aid may not be good.

(iii) The upper identification lamp should be put on, if it does not cause reflections which upset vision. All lights should be left on after ditching to facilitate search should the aircraft float for long.

5. Use of Flaps.

On most aircraft the flaps should be lowered to reduce the speed at which the aircraft can approach and touch down. It is better, if possible, to use a medium setting and not to lower them fully because little, if any, further reduction of speed is obtained by using more than half flap, while the aircraft approaches the sea more nose-down with a greater rate of descent. The steeper descent would be disadvantageous if the sea were met sooner than expected, and it increases the height needed to flatten out. On the other hand, all the evidence shows the importance of reducing speed to the minimum. Flaps should be lowered unless the Pilot's Notes for a specific type advise otherwise.

6. Approach Speed and Touch-down.

(i) Unless power is available symmetrically, the normal glide approach speed should be used. This speed will ensure adequate control and some margin of speed after flattening out with which the pilot can hold off a little or drop the aircraft to avoid striking the tail on a wave crest or swell top and so causing the aircraft to dive in.

(ii) Normally the pilot should hold off until all excess speed is lost and strike the sea at the normal three-point landing attitude (slow landing for tricycles).

7. Use of Engines.

(i) The value of power in ditching is so considerable that the pilot should always ditch if possible before fuel is quite exhausted, when it has become certain that the coast cannot be reached.

(ii) If only one engine of a twin is available, a little power should be used to flatten the approach; but the engine should not be used to such an extent that the aircraft cannot be turned against it right down to the stall, and it should not be opened up in the final stages. The power that can be used will vary with the type; on some aircraft it may be inadvisable to use the engine at all.

(iii) If two engines on one side are alone available out of four, use the inner engine only.

(iv) If power is available symmetrically, it should be used to the full if necessary-to secure the flattest possible approach and the slowest possible touch-down.

NOTE.-Propellers of engines that have failed or are not to be used in the ditching should he feathered.

8. Direction of Approach.

(i) The approach should be upwind in small, short waves. In big waves or steep swell, however-unless it is a really long ocean swell-it is better to ditch along the wave crests or swell top, unless doing so involves ditching in a very strong cross-wind. The danger of nosing into waves or swell is generally greater than the danger involved in ditching across wind. (This applies particularly to the smaller aircraft.)

(ii) When ditching across wind drift may be taken off as the sea is approached by sideslipping up wind; but generally drift is not dangerous. (Sideslip will be gauged by reference to the waves, which will be travelling down wind; this will leave a slight downwind drift, which is in the safe direction.)

(iii) When ditching by moonlight, if the direction of approach is not fixed by wind or swell, it is advantageous to ditch with the moon on the port bow.

9. Gauging Height.

(i) Judgment of height is not easy over the sea, especially when it is calm, and at night. But it is important to flatten out as accurately as possible.

(ii) The aneroid altimeter is useless for this purpose. On some aircraft the trailing aerial can be used, -the W.O. signalling the Captain when the current drops on the weight hitting the sea. Alternatively, the aerial may be engaged with an insulated hook held in the hand, which will feel the impact. A suitable ditching station close to the W.O.'s station is essential and this system must not be used if the radio is in the nose.

10. Direction of Wind.

(i) Waves-not swell¹-move down wind and the wave pattern indicates the line of the wind, though doubt may remain as to which way the wind blows along the line. Waves cannot, however, be taken to move with the wind close inshore or in fast moving estuaries.

1 Swell is the undulating movement of the surface caused by past or distant disturbances by wind; the (peakier) waves are caused by the immediate action of wind.

(ii) If the waves are breaking, they break downwind and this may be observed from a low height; but if the waves are running across a swell, the direction of breaking is not a reliable indicator of wind direction.

(iii) Spray blown off waves is a reliable indicator.

(iv) Wind direction may be obtained by dropping a smoke float. Smoke from a ship may be misleading, since the trail lies along a resultant line of wind speed and ship's motion; but some indication may be obtained from smoke from ships, or from the set of sails.

(v) When the surface is not broken, gusts may sometimes be observed rippling the surface in great sweeps, which indicate the direction of the wind.

11. Strength of the Wind.

(i) The strength of the wind may be gauged from the appearance of the sea, but only .if the wind has been blowing with the same force and direction for some time. The wind will be stronger than the sea suggests if it is freshening, blowing off a nearby shore, running with swell and tide, or during heavy rain. Moreover, breaking of waves may be due to shallow water.

(ii) With these cautions in mind, indications are:

A few "white horses" .. .. 10 to 20 m.p.h.

Many "white horses" .. .. 20 to 30 m.p.h.

Streaks of foam along ,wind . . 30 to 40 m.p.h.

Spray from crests 40 to 50 m.p.h.

12. State of the Sea.

(i) The sea always appears from the air to be more calm than it really is. In particular, swell can only be properly appreciated from quite close to the surface, and it may be of far greater consequence in ditching than the more obvious, but much smaller, waves.

(ii) If the wind is not. moving with the swell but across it, a cross-sea is created with waves running in a different direction from that of the swell.

(iii) If it is possible to fly low over the sea to study its surface before ditching, the observation so made may be very helpful. But pilots should endeavour to have constantly in mind the state of the sea and-wind. rather than leave observation and estimation till emergency arises, just, as when flying over land they bear in mind the features of the country over which they are flying.

13. Behaviour of Aircraft at Impact.

(i) With the aircraft alighting in a three-pointer attitude there will be a small primary impact as the rear of the aircraft strikes. A more or less severe secondary impact will follow, with generally a violent deceleration; the nose will tend to bury as the aircraft is brought to rest.

(ii) The nose should always be held well up after the first impact. If the alighting has been made too fast, the aircraft may bounce; the control column should be held hard back.

(iii) The aircraft may slew to one side after impact.

14. Special Notes on the Single-Seater Fighter.

(i) In general, the pilot should, if possible, abandon the R.A.F. single-seater fighter by parachute. The Hurricane may he expected to dive in if ditched at a relative sea speed of more than 55 m.p.h.; and the Spitfire to dive if the relative speed exceeds 75 m.p.h. On the other hand, the Fulmar has excellent ditching characteristics.

(ii) Diving does not, however, necessarily involve serious injury to the pilot and he is not precluded by this advice from flying towards a ship or friendly coast at the risk of having to ditch.

(iii) The advice in earlier paragraphs is, in general, applicable to the fighter ditching. Reduction of speed by use of flaps and, if possible, engine is especially important; if the flaps cannot be lowered part way they should be lowered fully. It is important to ditch up wind unless there is a steep swell; and essential to ditch along a steep swell to avoid nosing into it.

15. Ditching near Shipping.

If possible, the aircraft should be ditched well ahead on the ship's track.

PART IV-NOTE H - SEA RESCUE EQUIPMENT AND PROCEDURE

(Notes for all members of air crews)

1. Warning to Crew.

(i) The Captain will give the executive order "Dinghy, dinghy prepare for ditching", and each member of the crew will acknowledge, "Navigator ditching . . . etc."

(ii) Intercomm. should be duplicated by a call light signal "DDD".

(iii) The member of the crew nearest the Wireless Operator should also give him verbal warning.

2. Navigator's Duties.

(i) The Navigator should have a constant appreciation of WS & D and his DR and fixed position. He should always be aware of fuel consumption in relation to his ETA.

(ii) On the Captain's executive order he should:

(a) calculate position;

(b) pass DR position to W.O. with track and ground speed made good;

(d) calculate estimated position of ditching and pass to W.O.;

(e) inform Captain of surface WS & D;

(f) make out air and dinghy pigeon release messages;

(g) destroy secret papers and place charts (with latest position marked) in satchel.

3. Wireless Operator's Duties.

(i) If on Group frequency make first signal on that frequency and then change over to allotted MFDF section.

(ii) Turn IFF to emergency.

(iii) According to situation use one of the three priority calls:

(a) SOS I am in need of immediate assistance;

(b) I may require assistance;

(c) I may be forced to land without further signal. Give a time and position to the signal. It is better to make a signal than to remain silent. Cancel if no longer applicable.

(iv) Transmit track and ground speed made good.

(v) Pass fixes and bearings to Navigator.

(vi) Receive estimated position of ditching from Navigator. Transmit.

(vii) Clamp down key on Captain's order and move to ditching station.

(viii) Destroy secret papers.

(ix) If possible, use trailing aerial as an altimeter.

4. Single Seater Pilot's Signal Procedure.

(i) Make R.T. distress call and state "Bale out" or "Ditching".

(ii) Request accompanying aircraft to retransmit from over ditching position.

5. Captain's Duties.

(i) Open bomb doors, jettison, and close doors. Inflate flotation bags, if fitted.

(ii) Jettison fuel and close cocks. (On some aircraft flaps must first be lowered.)

(iii) Have Sutton harness secured (in full back position).

(iv) Jettison pilot's upper exit.

(v) Check undercarriage up, and lower flaps to ditching setting.

(vi) Order W.O. to his ditching station. (He should remain at his set as long as possible.)

(vii) Warn crew when ditching is imminent.

(viii) Switch on lamps as required.

6. Ditching Stations.

(i) The best position is sitting facing aft with the back and head against a solid structure. If, however, the head comes above the structure the hands must be clasped behind it to prevent it from being forced back.

(ii) The next best position is lying with head aft and the feet against a solid structure, with knees bent to avoid injury to the legs.

NOTE.-The rear of the bomb cell should not be used as a ditching station, because it is likely it will be forced inward and water will rush in there.

(iii) Straps should only be used if a shortage of suitable ditching stations forces a member of the crew to remain at his seat, as they may impede rapid egress. (The . pilot must be strapped in.)

7. Personal Equipment.

(i) Life jackets must be worn at all times with leg straps secured.

(ii) They may be fully inflated before ditching if the upper exits are large; but otherwise they should only be partly inflated and filled at once on leaving the exit.

(iii) Parachute harness should be removed if practicable (except when attached to the single seater dinghy).

(iv) Helmets should be retained for protection in the dinghy. Leads should be tucked firmly within the life jacket below the V of the neck at the top tie.

(v) Remove collar and tie, if worn.

(vi) Stowed sea rescue equipment should not be removed from its stowage near the exits before ditching.

8. Important Warning.

The crew must not relax or move until the aircraft has come to rest. They must be prepared for a double impact, the first when the aft parts of the aircraft strike and a second greater shock as the fore parts reach the water; also for the aircraft to slew to one side.

9. Release of Dinghy.

(i) Reliance should not be placed on the automatic inflation of the dinghy. Operate the manual release when the aircraft has come to rest; but do not touch the release before this, or accidental release may cause loss of the dinghy.

(ii) One of the crew should be detailed to assist the dinghy from its stowage into the water, to see that cordage does not become entangled, and that the dinghy is not carried under wing or fuselage, or punctured by some jagged edge or point.

(iii) If the dinghy should inflate upside down and cannot be righted from the wing, one man should jump into the sea and

(a) grasping the handling patches on its bottom with both hands, haul on them with knees on the buoyancy chamber, leaning back prepared to become submerged for a moment; or

(b) if there are no handling patches, place the toe on the bottom of the ladder and haul on the two nearest stabilising pockets, leaning back as above.

NOTE.-Do not jump on to the inverted dinghy, as that will expel air trapped beneath it and make righting more difficult.

10. Boarding the Dinghy.

(i) As soon as the aircraft comes to rest the crew should collect equipment and leave in order by the hatches as detailed in the Dinghy Drill.

(ii) Do not jump into the dinghy; it may damage it.

(iii) To board from the sea, grasp the ratlines with one hand and the bottom rung of the ladder with the other, pushing it down to help insert the foot; then pull up with both hands on the ratlines.

NOTE.-A fully inflated life jacket helps in boarding from the sea. There is a rescue line coiled on the dinghy to help crew to reach the dinghy.

11. After Boarding.

(i) Cut the painter with the floating knife (carried near the point of attachment of the painter).

(ii) Paddle away from the aircraft; but keep nearby while it floats to increase the chance of being located.

(iii) Check for leaks and fill with stoppers provided. Connect topping bellows and inflate till rigid; topping up may assist crew in the water in boarding. Bale out water.

(iv) Rig the dinghy cover.

NOTE.-Clothing should not be taken off, whether wet or dry. It is important to keep dry if possible.

12. The Single-Seat Dinghy.

(i) Pull in on the lead and, if the dinghy has not left the pack, rip off the cover and grasp the bottle. Pull out the locking pin and slowly unscrew the valve (one turn opens fully). Inflate slowly, assisting the dingy to unfold.

(ii) Board by the narrow end, aided by the loop handles. If the other end rises, let go and give a little push to fill the water pocket.

(iii) When aboard throw out the drogue to make the dinghy ride the waves better and ship less water.

(iv) Should the dinghy capsize, remove the hood and the apron elastic and slide out head first.

(v) This dinghy paddles well, but the water pocket must be collapsed and the drogue hauled in. It can be sailed by means of the weather apron.

(vi) A telescopic mast and red sail enable the dinghy to be sailed within 30° to either side of down wind. The mast rests on a thwart in two sections, which can be parted for use as paddles. Rigging instructions are on the containing bag, and sailing instructions are on the sail.

Note :

(a) The sail should not be rigged, or sailing attempted, in winds of over 35 m.p.h.

(b) Remain attached to the dinghy in rough weather.

13. Welfare while waiting Rescue.

(i) Although rescue may generally be expected much sooner, strict rationing of food and water should be made on a six days basis (plus extra days in the most adverse circumstances at the Captain's discretion). The provisions consist of water (the most important) solid foods and "energy tablets" (observe strictly the instructions on the container). Note that alcohol increases the dangers of exposure and is not to be carried.

(ii) Gentle exercise is important to promote circulation and relieve strain from cramped conditions. Suitable exercises should be done slowly, a little at a time, at frequent intervals. Start with the hands and feet working together.

14. Aids to being Located.

(i) Yellow skull caps should be worn and put on before ditching.

(ii) Fluorescine Blocks produce a vivid streak visible for several miles. Each block lasts 4 hours. Remove the cover and trail just awash.

(iii) Marine distress signals and any Very pistol cartridges taken in the dinghy must be kept dry.

(iv) Each member of the crew should carry a G.E.C. floating torch, which will show his position if he is in the water at night. It can be used for signalling. Torches should be tested periodically, without breaking the seal.

15. Dinghy Radio.

(i) The radio transmits on the international distress wave-length with a range of 20 miles on the 18 ft. mast. Instructions are on the set.

(ii) To erect the mast :-Join top to main mast; attach three pairs of guys to life line patches, centre pair downwind; fully extend top mast downwind; attach loading coil to main mast near the join; attach the short lead-wire to the top mast, leaving the long wire free to fix to the transmitter; fully extend main mast; pull mast upright and attach fourth guy lines; fit foot of mast into socket and adjust guy lines; connect to transmitter.

NOTE.-The dinghy cover should be rigged at all points before erecting the mast; all stabilising pockets should be open and drogue trailed.

WARNING.-If the mast falls it must not be held by the lower portions, but let fall and hauled up again by the guy lines.

(iii) Transmit at 15 and 45 minutes past the hour. -Transmit continuously if air or surface craft are in sight.

16. Pigeons.

(i) The bung lid should be closed when ditching is imminent and the breather opened when settled in the dinghy.

(ii) Each pigeon carries a prepared message with the aircraft number, date and colour code of station. The most important further information is whether the dinghy was released and manned, time and position of ditching, and time of release of pigeon.

(iii) If the Captain doubts the effectiveness of his radio trans-mission he may release one pigeon with:—A/Position/Time of origin, " A" signifies release from aircraft while airborne. Note that pigeons are not very dependable at night.

(iv) Wait for daylight before releasing from the dinghy. Indicate the time of ditching and of release, e.g.:-D/0240/0620 for ditched at 0240, released from dinghy at 0620 hours.

(v) If surface or aircraft are seen but fail to see the dinghy, and if a pigeon is available, send, e.g.: D/SV2 70°/3/1315 meaning searchers visible on bearing 2700 at 3 miles have not seen us-time of origin 1315 hours.

17. Stowage of Unofficial Equipment.

Stowage in the dinghy of equipment other than that laid down in the maintenance schedule is forbidden. It adds to the risk of entanglement, with possible loss of equipment or bursting of the dinghy, and it may cause the cover to break free in flight.

18. Further Information. Reference may be made to A.P.1182 Safety Equipment Manual, Vol. I.

PART IV. NOTE J - FIRE AT THE ENGINE IN FLIGHT

1. Immediate Preparation to Abandon Aircraft.

Fire at the engine may not be detected at once, and may spread quickly and cause the explosion of a fuel tank within a minute or two of its outbreak. On suspecting fire the pilot must, therefore, at once warn the crew to prepare to abandon aircraft.

2. Alternative Preparation for Crash Landing.

If the aircraft is at 1,000 ft. or less, so that it may not be possible for all the crew to escape by parachute, the pilot should consider making an immediate crash landing and, on deciding to do so, at once warn the crew to take up crash stations.

3. Action to Extinguish the Fire.

(i) The instruction given formerly to open the throttle is now discarded because the fire is not necessarily a carburettor fire which can be sucked through the engine. The burning substance may be fuel, or mixture, or oil, or hydraulic fluid, which is being pumped out through some fracture by the engine or one of its accessories. Although the fire may be stopped by operating the Graviner, it is liable to recur so soon as the brief action of the extinguisher is finished, if the engine is still running. The first action should, therefore, be to stop the engine by closing the throttle and feathering the propeller. The Graviner should not be operated until the engine has stopped or nearly stopped.

(ii) The ignition should not be switched off till the engine has more or less stopped because, if this is done, unburnt gases may leak from some fracture in the exhaust system and feed the flames around the engine.

(iii) The following actions should, therefore, be taken at once -in the following order in so far as action need be taken in order-after which the pilot should wait till the engine has stopped, or is revolving quite slowly.

(a) Close the throttle of the engine on fire.

(b) Feather its propeller.

When the engine has stopped or nearly stopped:

(a) Switch off.

(b) Operate the Graviner.

4. Action if Propeller is Non-feathering.

On aircraft with non-feathering propellers the same action should be followed as closely as possible:

(a) Close throttle.

(b) Propeller lever fully back.

Wait till the engine has slowed down to minimum r.p.m.

(a) Switch off.

(b) Operate Graviner.

5. Engine not to be Restarted.

The pilot must not attempt to restart an engine after a fire in its nacelle; for the fire is liable to recur and the Graviner will not act a second time.

6. Landing with Fire in an Aircraft.

It is seldom wise to land with fire in an aircraft when it is practicable to escape by parachute. The fire may spread disastrously when it is too late to jump, while the chance of saving the aircraft after landing may be small.

7. Fuel not to be Jettisoned.

Fuel must never be jettisoned while there is fire in any part of the aircraft.

8. Assistance in the Event of Fire in Take-off.

The second pilot's seat should be occupied by some member of the crew to render assistance to the pilot in the event of a fire occurring during take-off, when the pilot may be fully occupied in controlling the aircraft.

APPENDIX

Approximate True Speed at given I.A.S.

THE diagram shows how the true airspeed at any given indicated airspeed varies with altitude. (The I.A.S. must, of course, first be corrected for Instrument and Position Errors.) The central graph refers to the I.C.A.N. Standard Atmosphere and gives the factor by which the Rectified A.S. is to be multiplied when the atmospheric temperature is that assumed in the I.C.A.N. Standard (middle temperature graph at foot.) The curves on either side refer to average temperatures in tropical summer and in sub-arctic winter conditions respectively.

For example, an I.A.S. of 200 m.p.h. at 25,000 ft. is a true air-speed of approximately 1.5 X 200=300 m.p.h. at a temperature of about – 35°C. (I.C.A.N. figure). It would be about 315 m.p.h. at a tropical summer temperature of about – 5° and about 290 m.p.h. at a sub-arctic winter temperature of about -50°C.

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